ia64/linux-2.6.18-xen.hg

view net/ax25/ax25_subr.c @ 673:3161879fdf22

[IA64] xencomm: support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap

support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Tue Sep 16 21:26:15 2008 +0900 (2008-09-16)
parents 831230e53067
children
line source
1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
8 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
9 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
10 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
11 */
12 #include <linux/errno.h>
13 #include <linux/types.h>
14 #include <linux/socket.h>
15 #include <linux/in.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/timer.h>
19 #include <linux/string.h>
20 #include <linux/sockios.h>
21 #include <linux/net.h>
22 #include <net/ax25.h>
23 #include <linux/inet.h>
24 #include <linux/netdevice.h>
25 #include <linux/skbuff.h>
26 #include <net/sock.h>
27 #include <net/tcp_states.h>
28 #include <asm/uaccess.h>
29 #include <asm/system.h>
30 #include <linux/fcntl.h>
31 #include <linux/mm.h>
32 #include <linux/interrupt.h>
34 /*
35 * This routine purges all the queues of frames.
36 */
37 void ax25_clear_queues(ax25_cb *ax25)
38 {
39 skb_queue_purge(&ax25->write_queue);
40 skb_queue_purge(&ax25->ack_queue);
41 skb_queue_purge(&ax25->reseq_queue);
42 skb_queue_purge(&ax25->frag_queue);
43 }
45 /*
46 * This routine purges the input queue of those frames that have been
47 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
48 * SDL diagram.
49 */
50 void ax25_frames_acked(ax25_cb *ax25, unsigned short nr)
51 {
52 struct sk_buff *skb;
54 /*
55 * Remove all the ack-ed frames from the ack queue.
56 */
57 if (ax25->va != nr) {
58 while (skb_peek(&ax25->ack_queue) != NULL && ax25->va != nr) {
59 skb = skb_dequeue(&ax25->ack_queue);
60 kfree_skb(skb);
61 ax25->va = (ax25->va + 1) % ax25->modulus;
62 }
63 }
64 }
66 void ax25_requeue_frames(ax25_cb *ax25)
67 {
68 struct sk_buff *skb, *skb_prev = NULL;
70 /*
71 * Requeue all the un-ack-ed frames on the output queue to be picked
72 * up by ax25_kick called from the timer. This arrangement handles the
73 * possibility of an empty output queue.
74 */
75 while ((skb = skb_dequeue(&ax25->ack_queue)) != NULL) {
76 if (skb_prev == NULL)
77 skb_queue_head(&ax25->write_queue, skb);
78 else
79 skb_append(skb_prev, skb, &ax25->write_queue);
80 skb_prev = skb;
81 }
82 }
84 /*
85 * Validate that the value of nr is between va and vs. Return true or
86 * false for testing.
87 */
88 int ax25_validate_nr(ax25_cb *ax25, unsigned short nr)
89 {
90 unsigned short vc = ax25->va;
92 while (vc != ax25->vs) {
93 if (nr == vc) return 1;
94 vc = (vc + 1) % ax25->modulus;
95 }
97 if (nr == ax25->vs) return 1;
99 return 0;
100 }
102 /*
103 * This routine is the centralised routine for parsing the control
104 * information for the different frame formats.
105 */
106 int ax25_decode(ax25_cb *ax25, struct sk_buff *skb, int *ns, int *nr, int *pf)
107 {
108 unsigned char *frame;
109 int frametype = AX25_ILLEGAL;
111 frame = skb->data;
112 *ns = *nr = *pf = 0;
114 if (ax25->modulus == AX25_MODULUS) {
115 if ((frame[0] & AX25_S) == 0) {
116 frametype = AX25_I; /* I frame - carries NR/NS/PF */
117 *ns = (frame[0] >> 1) & 0x07;
118 *nr = (frame[0] >> 5) & 0x07;
119 *pf = frame[0] & AX25_PF;
120 } else if ((frame[0] & AX25_U) == 1) { /* S frame - take out PF/NR */
121 frametype = frame[0] & 0x0F;
122 *nr = (frame[0] >> 5) & 0x07;
123 *pf = frame[0] & AX25_PF;
124 } else if ((frame[0] & AX25_U) == 3) { /* U frame - take out PF */
125 frametype = frame[0] & ~AX25_PF;
126 *pf = frame[0] & AX25_PF;
127 }
128 skb_pull(skb, 1);
129 } else {
130 if ((frame[0] & AX25_S) == 0) {
131 frametype = AX25_I; /* I frame - carries NR/NS/PF */
132 *ns = (frame[0] >> 1) & 0x7F;
133 *nr = (frame[1] >> 1) & 0x7F;
134 *pf = frame[1] & AX25_EPF;
135 skb_pull(skb, 2);
136 } else if ((frame[0] & AX25_U) == 1) { /* S frame - take out PF/NR */
137 frametype = frame[0] & 0x0F;
138 *nr = (frame[1] >> 1) & 0x7F;
139 *pf = frame[1] & AX25_EPF;
140 skb_pull(skb, 2);
141 } else if ((frame[0] & AX25_U) == 3) { /* U frame - take out PF */
142 frametype = frame[0] & ~AX25_PF;
143 *pf = frame[0] & AX25_PF;
144 skb_pull(skb, 1);
145 }
146 }
148 return frametype;
149 }
151 /*
152 * This routine is called when the HDLC layer internally generates a
153 * command or response for the remote machine ( eg. RR, UA etc. ).
154 * Only supervisory or unnumbered frames are processed.
155 */
156 void ax25_send_control(ax25_cb *ax25, int frametype, int poll_bit, int type)
157 {
158 struct sk_buff *skb;
159 unsigned char *dptr;
161 if ((skb = alloc_skb(ax25->ax25_dev->dev->hard_header_len + 2, GFP_ATOMIC)) == NULL)
162 return;
164 skb_reserve(skb, ax25->ax25_dev->dev->hard_header_len);
166 skb->nh.raw = skb->data;
168 /* Assume a response - address structure for DTE */
169 if (ax25->modulus == AX25_MODULUS) {
170 dptr = skb_put(skb, 1);
171 *dptr = frametype;
172 *dptr |= (poll_bit) ? AX25_PF : 0;
173 if ((frametype & AX25_U) == AX25_S) /* S frames carry NR */
174 *dptr |= (ax25->vr << 5);
175 } else {
176 if ((frametype & AX25_U) == AX25_U) {
177 dptr = skb_put(skb, 1);
178 *dptr = frametype;
179 *dptr |= (poll_bit) ? AX25_PF : 0;
180 } else {
181 dptr = skb_put(skb, 2);
182 dptr[0] = frametype;
183 dptr[1] = (ax25->vr << 1);
184 dptr[1] |= (poll_bit) ? AX25_EPF : 0;
185 }
186 }
188 ax25_transmit_buffer(ax25, skb, type);
189 }
191 /*
192 * Send a 'DM' to an unknown connection attempt, or an invalid caller.
193 *
194 * Note: src here is the sender, thus it's the target of the DM
195 */
196 void ax25_return_dm(struct net_device *dev, ax25_address *src, ax25_address *dest, ax25_digi *digi)
197 {
198 struct sk_buff *skb;
199 char *dptr;
200 ax25_digi retdigi;
202 if (dev == NULL)
203 return;
205 if ((skb = alloc_skb(dev->hard_header_len + 1, GFP_ATOMIC)) == NULL)
206 return; /* Next SABM will get DM'd */
208 skb_reserve(skb, dev->hard_header_len);
209 skb->nh.raw = skb->data;
211 ax25_digi_invert(digi, &retdigi);
213 dptr = skb_put(skb, 1);
215 *dptr = AX25_DM | AX25_PF;
217 /*
218 * Do the address ourselves
219 */
220 dptr = skb_push(skb, ax25_addr_size(digi));
221 dptr += ax25_addr_build(dptr, dest, src, &retdigi, AX25_RESPONSE, AX25_MODULUS);
223 ax25_queue_xmit(skb, dev);
224 }
226 /*
227 * Exponential backoff for AX.25
228 */
229 void ax25_calculate_t1(ax25_cb *ax25)
230 {
231 int n, t = 2;
233 switch (ax25->backoff) {
234 case 0:
235 break;
237 case 1:
238 t += 2 * ax25->n2count;
239 break;
241 case 2:
242 for (n = 0; n < ax25->n2count; n++)
243 t *= 2;
244 if (t > 8) t = 8;
245 break;
246 }
248 ax25->t1 = t * ax25->rtt;
249 }
251 /*
252 * Calculate the Round Trip Time
253 */
254 void ax25_calculate_rtt(ax25_cb *ax25)
255 {
256 if (ax25->backoff == 0)
257 return;
259 if (ax25_t1timer_running(ax25) && ax25->n2count == 0)
260 ax25->rtt = (9 * ax25->rtt + ax25->t1 - ax25_display_timer(&ax25->t1timer)) / 10;
262 if (ax25->rtt < AX25_T1CLAMPLO)
263 ax25->rtt = AX25_T1CLAMPLO;
265 if (ax25->rtt > AX25_T1CLAMPHI)
266 ax25->rtt = AX25_T1CLAMPHI;
267 }
269 void ax25_disconnect(ax25_cb *ax25, int reason)
270 {
271 ax25_clear_queues(ax25);
273 ax25_stop_t1timer(ax25);
274 ax25_stop_t2timer(ax25);
275 ax25_stop_t3timer(ax25);
276 ax25_stop_idletimer(ax25);
278 ax25->state = AX25_STATE_0;
280 ax25_link_failed(ax25, reason);
282 if (ax25->sk != NULL) {
283 bh_lock_sock(ax25->sk);
284 ax25->sk->sk_state = TCP_CLOSE;
285 ax25->sk->sk_err = reason;
286 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
287 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
288 ax25->sk->sk_state_change(ax25->sk);
289 sock_set_flag(ax25->sk, SOCK_DEAD);
290 }
291 bh_unlock_sock(ax25->sk);
292 }
293 }